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TV-B-Gone Hat 

Make] Projects 

TV-B-Gone Hat 

Written By: Mitch Altman 



Heat gun (1) 

TV-B-Gone Kit (1) 

or hair drver, or liahter 


Baseball cap (1) 

Hot glue gun (1) 

or anv other hat with a visor 



Tactile switch (1) 

Needlenose pliers M) 


Thread (1) 


Heat-shrink tubinq (1) 


Heat-shrink tubing (1) 


Wire (about 2") 


Permanent marker (1) 
or paint 


Battery (2) 


"Hey, you mind turning that thing off?" Simple enough question, but I got tired of people 
looking at me like I'm from Mars. When a TV is on in the room, I can't think. I just stare at 
the thing and drool. 

So I invented TV-B-Gone, a key chain that stealthily turns off just about any television. 
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TV-B-Gone Hat 

When the TVs turn off, people turn on, engage in conversation, read, eat, and perform all 
sorts of human activities. Peace happens. 

I recently teamed up with prolific kit maker Limor Fried to create a $20 kit version of the 
original TV-B-Gone key chain. This version works up to 40 yards away, and it's totally 
hackable; the entire project is open source and documented at . Here's how I built one into a baseball cap that lets me look 
at almost any TV, touch the top, and watch with glee as it shuts off. 

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TV-B-Gone Hat 

Step 1 — How TV-B-Gone Works 

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TV-B-Gone Hat 


1.2 milliseconds on-time 

1.0 milliseconds off-time 

7.1 milliseconds on-time 

27.8 milliseconds off-time 

1.2 milliseconds on-time - 

1.0 milliseconds off-time - 

7.1 milliseconds on-time - 

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• TV remote controls all work the 
same way: by transmitting coded 
patterns of 940nm wavelength 
infrared to the television's remote 
control receiver, somewhat like 
sending Morse code with a 
flashlight. The receiver watches for 
blinking IR, and when it sees 
patterns it recognizes, performs 
the corresponding functions on the 
TV. To avoid accidental triggering 
by reflected light in the room, 
receivers only respond to IR light 
that pulses at a specific carrier 

• For our TV-B-Gone, we don't care 
about couch-surfing functionality; 
all we need is the code for turning a 
TV off. (Because remotes have just 
one on/off button, this is the same 
as the code to turn it on, and the 
TVs current state determines 
which new state to toggle to.) 

• For example, to turn off a JVC TV, 
you blink the pattern shown in 
Figure A using a carrier frequency 
of 54kHz. The entire sequence 
lasts only a tiny fraction of a 
second, so there's no perceivable 

• Different manufacturers' IR 
standards vary, but they all use 
rapid blinking of an even faster 
carrier frequency. TV-B-Gone 
transmits the on/off button codes 
for most TVs, one right after the 

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TV-B-Gone Hat 

other. So it works like other 
remotes, but with just one button. 

Step 2 — Assemble the kit. 

• First I built the TV-B-Gone kit itself. I already knew how to do this, but you can follow the 
excellent instructions at . 

Step 3 — Install the switch. 

• Take out the batteries and unsolder 
the battery leads from the board. 
Then bend the 4 legs of the tactile 
switch apart so they're flat, and 
hot-glue the switch to the button on 
top of the cap. 

• Use needlenose pliers to push 
some of the wire-wrap wire through 
the hat fabric near the button. Pull 
enough wire through on the 
underside of the hat to reach the 
end of the visor. 

• Repeat using a second piece of 
wire, then solder the wires to 2 of 
the switch's legs on the same side, 
clip off the other 2 legs, and cover 
the soldered joints with 1/16" heat- 
shrink tubing. 

• If you use a lighter, be careful not 
to place the tubing (or the hat) 
directly in the flame. Hold the flame 
just above the tubing and move it 
around slowly until it's fully shrunk. 

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TV-B-Gone Hat 

Step 4 

• Use a needle and thread to sew the 
2 wires to the inside of the hat. I 
used 5 loops for each, tying them 
off with a square knot. 
Alternatively, you can also use hot 

Step 5 

• Position the assembled TV-B-Gone 
at the edge of the visor of the hat, 
with the IR emitters just inside the 
brim, pointing outward. Cut the 
wires from the hat-top switch so 
they extend just past the switch 
button on the circuit board. 

Step 6 — Install the battery pack. 

• Center the battery pack under the cap's dome with its 2 wires facing forward, toward the 
visor. Hot-glue the battery pack in place, then sew (or hot-glue) its wires to follow the 
same paths as the switch wires. 

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TV-B-Gone Hat 

Step 7 — Install the TV-B-Gone. 

• Trim and solder the wires to the 
battery terminals on the circuit 
board (BATT), red to + and black to 
-, covering the connections with 
1/16" heat-shrink tubing. 

• Trim and solder the 2 wires from 
the tactile switch and solder them 
to the 2 connected terminals for the 
onboard switch (S1). It does not 
matter which wire goes to which 

Step 8 — Test. 

• Insert 2 batteries into the holder. The visible LED (LED5) should start blinking. If not, 
immediately take the batteries out and check that the battery leads aren't reversed. 

• You can also confirm that all 4 of the TV-B-Gone's IR emitters are blinking by watching 
them through a digital camera (most cameras can see IR). 

• After the TV-B-Gone turns itself off, pushing the button on top of the hat should restart the 
transmission sequence. If not, double-check the wires running from the hat switch to the 

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TV-B-Gone Hat 

Step 9 — Final assembly. 

• Remove the batteries, then cover 
the circuit board with a 2"-long 
piece of 1" heat-shrink tubing and 
shrink it in place. 

• After shrinking, cut little pieces out 
of the tubing to expose the visible 
light and the onboard switch. 

• Hot-glue the covered board to the 
underside of the visor with the IR 
emitters facing forward, as before. 
Finally, use a colored marker or 
paint to conceal the silver parts of 
the hat switch. 

Step 10 — A Real-Life TV Story 

• We walk into a restaurant. Nice place — except there are 3 huge-screen TVs blaring from 
different corners. No one is watching any of them, so off they go. None of the customers 
even seem to notice, yet the waiter feels obliged to turn them back on. 

• No problem — off they go again. The waiter calls the manager, who grabs the remote 
control and turns them on again. Triumphant, they start to walk away. Off go the TVs once 
more. While they're standing there, dumbfounded, I switch them all on. Then off. Their 
shoulders slump in unison, admitting defeat. We enjoy our meal and conversation. 

• I love my TV-B-Gone hat. 

This project first appeared in MAKE Volume 13 . 
Related Posts on Make: Online: 

TV-B-Gone Hoodie 

© Make Projects 

Page 8 of 9 

TV-B-Gone Hat 

Double the Range of Your TV-Be-Gone 

Ultra TV-B-Gone . 

last generated on 2012-1 1-03 01:11:26 AM. 

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